The Earth’s water cycle is accelerating as a result of climate change. According to new satellite data, fresh waters are getting colder and salty waters are getting even saltier at an ever-faster rate around the world. Ocean salinity is essential to understanding ocean circulation, one of the key factors in understanding global climate. According to the researchers, if this pattern continues, it will lead to more thunderstorms.
In research led by the Institut de Ciencies del Mar (ICM) – CSIC based in Barcelona, they have discovered that the water cycle is accelerating as the temperature of the ocean water increases, which causes greater evaporation in the sea. Much of this vapor will fall on the sea as rain once the cycle is complete, but 10% will fall as rain on land, which could bring significant changes to the day-to-day life of human beings. Because this, in turn, will increase rainfall in other parts of the world, diluting some bodies of water to make them even less salty. This acceleration of the water cycle could have a profound impact on modern society, causing droughts and water shortages, as well as more intense storms and floods.
“We have been able to see that surface salinity is showing an intensification of the water cycle that does not occur with subsoil salinity,” explains Estrella Olmedo, lead author of the study published in the journal Scientific Reports . “Specifically, in the Pacific we have seen that surface salinity decreases more slowly than subsurface salinity and, in this same region, we have observed an increase in sea surface temperature.”
As global temperatures rise…
This is a worrying pattern.
“The acceleration of the water cycle has implications both in the ocean and on the continent, where storms can be increasingly intense,” Olmedo said. “This greater amount of water circulating in the atmosphere could also explain the increase in precipitation that is being detected in some polar areas, where the fact that it rains instead of snows is accelerating the melting.”
If the water cycle speeds up with global warming, it could have a profound impact on modern society and may even have started to speed up snow melt, as rainfall has increased in the polar regions as well.
“This greater amount of water circulating in the atmosphere could also explain the increase in precipitation that is being detected in some polar areas, where the fact that it rains instead of snowing is accelerating the melting,” explains the mathematician Olmedo.
The water cycle regulates all water on Earth
The same water that we drink every day is exactly the same that the dinosaurs drank when they ruled the Earth , before becoming extinct 65 million years ago. It is the same liquid. Which means that today’s water was once in ice caps, glaciers, swamps, and even quenched the thirst of dinosaurs.
But with the cycle accelerating, more intense thunderstorms are likely to form, as well as flooding. It can also lead to faster melting of glaciers and ice caps with increased precipitation in the polar regions, while conversely already dry regions will become even drier.
These findings are the result of the use of algorithms and other data analysis tools that the ICM-CSIC has generated from the SMOS space mission of the European Space Agency (ESA). Satellite data, unlike subsurface data – which is usually measured with ocean buoys – allows researchers to analyze the effect of stratification on very large regions of the ocean.
The data isn’t rosy: recent climate models predict that for every extra degree Celsius of warming, the Earth’s water cycle could intensify by as much as 7%. The only way to fix this future problem is to limit global warming. For now, the most ambitious goal of the Paris Agreement, keeping warming to 1.5°C or less, has only less than a 10% chance of being achieved, according to experts.
Referencia: Olmedo, E., Turiel, A., González-Gambau, V. et al. Increasing stratification as observed by satellite sea surface salinity measurements. Scientific Reports 12, 6279 (2022). https://doi.org/10.1038/s41598-022-10265-1
